1. Field of the Invention
The invention relates to battery power supplies for electric devices. In particular, the invention relates to rechargeable battery packs which can be recharged in either a recessed receptacle, the receptacle being often referred to as an "outlet," or in a non-recessed receptacle and wherein the battery pack is adapted to reside within a pocket of a portable, cordless, electric device for powering the device.
2. Description of the Prior Art
The availability of rechargeable batteries has led to a variety of rechargeable, battery-operated, portable, cordless devices including grass shears, hedge trimmers, shrub trimmers, lawn mowers, sprayers, soldering irons, flashlights, screwdrivers, and the like. In some cases, the batteries are housed in a nonremovable pack while the recharging circuitry is housed in a separate charging unit. In other cases, the charging circuitry is incorporated as a part of a rechargeable battery pack. It has also been previously proposed to provide a removable battery pack having its own recharging circuitry, the pack having conventional United States-type AC prongs and arranged so that the pack can be interconnected through the prongs to the device to be powered or through the same prongs to a conventional 120 volt United States-household receptacle for recharging. U.S. Pat. Nos. 3,275,819 and 3,281,636 and French Pat. No. 1.418.746 are illustrative of such devices. It has also been suggested to have a removable, rechargeable battery pack that could be connected to any one of several battery power consuming devices.
In a recent development described in U.S. Pat. No. 3,952,239, a system now on the market is directed to a range of cordless devices including grass shears, lanterns, drills, and shrub trimmers. Each device mates with a standardized power handle which serves both as a handle and a housing for a rechargeable battery.
As described in the commonly-assigned, copending application Ser. No. 607,376, now U.S. Pat. No. 4,084,123, the most recent known development in the art of battery power packs is the advent of a relatively flat, rectangular, box-shaped battery pack which fits into a mating pocket in a device. This battery pack carries a pair of standard AC prongs extending from a flat sidewall surface of the pack. The prongs are adapted for insertion into a standard United States-type, 120 volt, AC receptacle for charging the battery pack through rectifier means contained in the pack thus eliminating the need for a separate charger. When the battery pack is positioned in the respective pocket of the tool or device, a mechanical switch is actuated by mating formations on the pack and pocket and connects the battery pack in a discharge mode so that the particular tool or device can be powered through the batteries using the same set of AC prongs. Heavy duty tools or devices are provided with multiple pockets for the reception of a corresponding number of identical battery packs.
While adapted to receptacles of the type found in the United States, the rechargeable pack described in copending application Ser. No. 607,376 does not adapt to recharging conditions as are encountered in Europe and other areas of the world where recessed-type receptacles are employed.
U.S. Pat. Nos. 3,067,373 and 3,120,632 are illustrative of combined power unit-load unit assemblies which can be easily disconnected from the load unit and connected to any readily available source of alternating current such as a conventional household receptacle. Also, these patents illustrate prongs slidably arranged in the unit assembly.
Also, U.S. Pat. No. 3,996,546 is illustrative of a dual voltage, electrical plug which is adaptable to connect an appliance, such as an electric shaver, alternatively to sockets belonging to either one of two main supplies of differing voltage, e.g., 110 volt United States or 220 volt European.
With all of the foregoing considerations in mind, it thus becomes the object of this invention to provide a type of rechargeable battery pack which improves on the foregoing prior art and is adaptable for recharging in either flush or recessed-type receptacles, whether shallow or deeply recessed.